Fault States Diagnosis of Marine Diesel Engine Valve Based on a Modified VGG16 Transfer Learning Method

Figure 6

The PSD of ideal and noise disturbed vibration signals based on the normal exhaust valve: (a) PSD image from an ideal single-cycle combustion section, (b) PSD image from a noise disturbed single-cycle combustion section, (c) PSD image from an ideal single-cycle section, and (d) PSD image from a noise disturbed single-cycle section.

(a)

(b)

(c)

(d)